最近,在自动开放域对话框评估中应用预先接受训练的语言模型(PR-LM),有兴趣的兴趣。PR-LMS提供了满足多域评估挑战的有希望的方向。然而,不同PR-LMS对自动度量的性能的影响是不太理解的。本文审查了8种不同的PRM,并研究了三种不同对话评估基准的三种典型自动对话对话指标的影响。具体而言,我们分析PR-LMS的选择如何影响自动度量的性能。执行对每个度量的广泛相关分析以评估不同PR-LMS沿各种轴的影响,包括预训练目标,对话对话标准,模型规模和跨数据集鲁棒性。本研究有助于第一次全面评估不同PR-LMS对自动对话评估的影响。
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Chatbots are expected to be knowledgeable across multiple domains, e.g. for daily chit-chat, exchange of information, and grounding in emotional situations. To effectively measure the quality of such conversational agents, a model-based automatic dialogue evaluation metric (ADEM) is expected to perform well across multiple domains. Despite significant progress, an ADEM that works well in one domain does not necessarily generalize to another. This calls for a dedicated network architecture for domain generalization. To tackle the multi-domain dialogue evaluation task, we propose a Panel of Experts (PoE), a multitask network that consists of a shared transformer encoder and a collection of lightweight adapters. The shared encoder captures the general knowledge of dialogues across domains, while each adapter specializes in one specific domain and serves as a domain expert. To validate the idea, we construct a high-quality multi-domain dialogue dataset leveraging data augmentation and pseudo-labeling. The PoE network is comprehensively assessed on 16 dialogue evaluation datasets spanning a wide range of dialogue domains. It achieves state-of-the-art performance in terms of mean Spearman correlation over all the evaluation datasets. It exhibits better zero-shot generalization than existing state-of-the-art ADEMs and the ability to easily adapt to new domains with few-shot transfer learning.
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聊天旨在跨越不同域的人类对话,例如普通的Chit-Chat,知识交流和角色接地对话。为了衡量此类会话代理人的质量,预计对话评估员也会在域中进行评估。但是,大多数最先进的自动对话评估指标(ADMS)不是用于多域评估的。我们有动力设计一般和强大的框架MDD-eval,解决问题。具体而言,我们首先将教师评估员与人类注释的数据一起培训,获取评级技能,以便在特定领域的坏人中讲述良好的对话响应,然后采取自我培训策略,以培训具有教师注释的新评估员的新评估人员域数据,有助于新评估程序遍历多个域。 MDD-EVAL在六个对话评估基准上进行了广泛评估。经验结果表明,在所有评估基准的平均矛盾的普通相关评分方面,MDD-ex律师框架在最先进的adms方面取得了强大的表现,绝对改善了7%。
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预先接受训练的语言模型的最新进展具有显着改善的神经反应生成。但是,现有方法通常将对话背景视为令牌的线性序列,并通过令牌级自我关注学习生成下一个单词。这些令牌级编码阻碍了话语中话语水平一致性的探索。本文介绍了对话贝特,这是一种新的会话响应生成模型,可以增强以前的基于PLM的对话模型。 DialogBert采用分层变压器架构。为了有效地捕捉话语中的话语水平一致性,我们提出了两种培训目标,包括蒙面的话语回归和分布式话语秩序与原始BERT训练相比。在三个多转对谈话数据集上的实验表明,在定量评估方面,我们的方法非常优于BART和Dialogpt等基线。人类评估表明,DialogBert比具有显着利润率的基线产生更加连贯,信息和人类的反应。
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Controllable Text Generation (CTG) is emerging area in the field of natural language generation (NLG). It is regarded as crucial for the development of advanced text generation technologies that are more natural and better meet the specific constraints in practical applications. In recent years, methods using large-scale pre-trained language models (PLMs), in particular the widely used transformer-based PLMs, have become a new paradigm of NLG, allowing generation of more diverse and fluent text. However, due to the lower level of interpretability of deep neural networks, the controllability of these methods need to be guaranteed. To this end, controllable text generation using transformer-based PLMs has become a rapidly growing yet challenging new research hotspot. A diverse range of approaches have emerged in the recent 3-4 years, targeting different CTG tasks which may require different types of controlled constraints. In this paper, we present a systematic critical review on the common tasks, main approaches and evaluation methods in this area. Finally, we discuss the challenges that the field is facing, and put forward various promising future directions. To the best of our knowledge, this is the first survey paper to summarize CTG techniques from the perspective of PLMs. We hope it can help researchers in related fields to quickly track the academic frontier, providing them with a landscape of the area and a roadmap for future research.
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最近,培训预培训方法在以任务为导向的对话框(TOD)系统中表现出了很大的成功。但是,大多数现有的预培训模型用于TOD专注于对话的理解或对话生成,但并非两者兼而有之。在本文中,我们提出了Space-3,这是一种新型的统一的半监督预培训的预训练的对话模型,从大规模对话CORPORA中学习有限的注释,可以有效地对广泛的下游对话任务进行微调。具体而言,Space-3由单个变压器中的四个连续组件组成,以维护TOD系统中的任务流:(i)对话框编码模块编码对话框历史记录,(ii)对话框理解模块以从任一用户中提取语义向量查询或系统响应,(iii)一个对话框策略模块,以生成包含响应高级语义的策略向量,以及(iv)对话框生成模块以产生适当的响应。我们为每个组件设计一个专门的预训练目标。具体而言,我们预先培训对话框编码模块,使用跨度掩码语言建模,以学习上下文化对话框信息。为了捕获“结构化对话框”语义,我们通过额外的对话注释通过新颖的树诱导的半监视对比度学习目标来预先培训对话框理解模块。此外,我们通过将其输出策略向量与响应响应的语义向量之间的L2距离最小化以进行策略优化,从而预先培训对话策略模块。最后,对话框生成模型由语言建模预先训练。结果表明,Space-3在八个下游对话框基准中实现最新性能,包括意图预测,对话框状态跟踪和端到端对话框建模。我们还表明,在低资源设置下,Space-3比现有模型具有更强的射击能力。
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We introduce a new language representation model called BERT, which stands for Bidirectional Encoder Representations from Transformers. Unlike recent language representation models (Peters et al., 2018a;Radford et al., 2018), BERT is designed to pretrain deep bidirectional representations from unlabeled text by jointly conditioning on both left and right context in all layers. As a result, the pre-trained BERT model can be finetuned with just one additional output layer to create state-of-the-art models for a wide range of tasks, such as question answering and language inference, without substantial taskspecific architecture modifications.BERT is conceptually simple and empirically powerful. It obtains new state-of-the-art results on eleven natural language processing tasks, including pushing the GLUE score to 80.5% (7.7% point absolute improvement), MultiNLI accuracy to 86.7% (4.6% absolute improvement), SQuAD v1.1 question answering Test F1 to 93.2 (1.5 point absolute improvement) and SQuAD v2.0 Test F1 to 83.1 (5.1 point absolute improvement).
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基于变压器的语言模型最近在许多自然语言任务中取得了显着的结果。但是,通常通过利用大量培训数据来实现排行榜的性能,并且很少通过将明确的语言知识编码为神经模型。这使许多人质疑语言学对现代自然语言处理的相关性。在本文中,我介绍了几个案例研究,以说明理论语言学和神经语言模型仍然相互关联。首先,语言模型通过提供一个客观的工具来测量语义距离,这对语言学家很有用,语义距离很难使用传统方法。另一方面,语言理论通过提供框架和数据源来探究我们的语言模型,以了解语言理解的特定方面,从而有助于语言建模研究。本论文贡献了三项研究,探讨了语言模型中语法 - 听觉界面的不同方面。在论文的第一部分中,我将语言模型应用于单词类灵活性的问题。我将Mbert作为语义距离测量的来源,我提供了有利于将单词类灵活性分析为方向过程的证据。在论文的第二部分中,我提出了一种方法来测量语言模型中间层的惊奇方法。我的实验表明,包含形态句法异常的句子触发了语言模型早期的惊喜,而不是语义和常识异常。最后,在论文的第三部分中,我适应了一些心理语言学研究,以表明语言模型包含了论证结构结构的知识。总而言之,我的论文在自然语言处理,语言理论和心理语言学之间建立了新的联系,以为语言模型的解释提供新的观点。
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This paper presents a new UNIfied pre-trained Language Model (UNILM) that can be fine-tuned for both natural language understanding and generation tasks. The model is pre-trained using three types of language modeling tasks: unidirectional, bidirectional, and sequence-to-sequence prediction. The unified modeling is achieved by employing a shared Transformer network and utilizing specific self-attention masks to control what context the prediction conditions on. UNILM compares favorably with BERT on the GLUE benchmark, and the SQuAD 2.0 and CoQA question answering tasks. Moreover, UNILM achieves new state-ofthe-art results on five natural language generation datasets, including improving the CNN/DailyMail abstractive summarization ROUGE-L to 40.51 (2.04 absolute improvement), the Gigaword abstractive summarization ROUGE-L to 35.75 (0.86 absolute improvement), the CoQA generative question answering F1 score to 82.5 (37.1 absolute improvement), the SQuAD question generation BLEU-4 to 22.12 (3.75 absolute improvement), and the DSTC7 document-grounded dialog response generation NIST-4 to 2.67 (human performance is 2.65). The code and pre-trained models are available at https://github.com/microsoft/unilm. * Equal contribution. † Contact person.
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基于检索的对话响应选择旨在为给定多转中下文找到候选集的正确响应。基于预先训练的语言模型(PLMS)的方法对此任务产生了显着的改进。序列表示在对话背景和响应之间的匹配程度中扮演关键作用。然而,我们观察到相同上下文共享的不同的上下文响应对始终在由PLM计算的序列表示中具有更大的相似性,这使得难以区分来自负面的正响应。由此激励,我们提出了一种基于PLMS的响应选择任务的新颖\ TextBF {f} ine- \ textbf {g}下载\ textbf {g} unfrstive(fgc)学习方法。该FGC学习策略有助于PLMS在细粒中产生每个对话的更可区分的匹配表示,并进一步提高选择正反应的预测。两个基准数据集的实证研究表明,所提出的FGC学习方法一般可以提高现有PLM匹配模型的模型性能。
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在这项工作中,我们探索如何学习专用的语言模型,旨在学习从文本文件中学习关键词的丰富表示。我们在判别和生成设置中进行预训练变压器语言模型(LMS)的不同掩蔽策略。在歧视性设定中,我们引入了一种新的预训练目标 - 关键边界,用替换(kbir)infifiling,在使用Kbir预先训练的LM进行微调时显示出在Sota上的性能(F1中高达9.26点)的大量增益关键酶提取的任务。在生成设置中,我们为BART - 键盘介绍了一个新的预训练设置,可再现与CATSeq格式中的输入文本相关的关键字,而不是Denoised原始输入。这也导致在关键词中的性能(F1 @ M)中的性能(高达4.33点),用于关键正版生成。此外,我们还微调了在命名实体识别(ner),问题应答(qa),关系提取(重新),抽象摘要和达到与SOTA的可比性表现的预训练的语言模型,表明学习丰富的代表关键词确实有利于许多其他基本的NLP任务。
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Masked language modeling (MLM) pre-training methods such as BERT corrupt the input by replacing some tokens with [MASK] and then train a model to reconstruct the original tokens. While they produce good results when transferred to downstream NLP tasks, they generally require large amounts of compute to be effective. As an alternative, we propose a more sample-efficient pre-training task called replaced token detection. Instead of masking the input, our approach corrupts it by replacing some tokens with plausible alternatives sampled from a small generator network. Then, instead of training a model that predicts the original identities of the corrupted tokens, we train a discriminative model that predicts whether each token in the corrupted input was replaced by a generator sample or not. Thorough experiments demonstrate this new pre-training task is more efficient than MLM because the task is defined over all input tokens rather than just the small subset that was masked out. As a result, the contextual representations learned by our approach substantially outperform the ones learned by BERT given the same model size, data, and compute. The gains are particularly strong for small models; for example, we train a model on one GPU for 4 days that outperforms GPT (trained using 30x more compute) on the GLUE natural language understanding benchmark. Our approach also works well at scale, where it performs comparably to RoBERTa and XLNet while using less than 1/4 of their compute and outperforms them when using the same amount of compute.
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Discriminative pre-trained language models (PLMs) learn to predict original texts from intentionally corrupted ones. Taking the former text as positive and the latter as negative samples, the PLM can be trained effectively for contextualized representation. However, the training of such a type of PLMs highly relies on the quality of the automatically constructed samples. Existing PLMs simply treat all corrupted texts as equal negative without any examination, which actually lets the resulting model inevitably suffer from the false negative issue where training is carried out on pseudo-negative data and leads to less efficiency and less robustness in the resulting PLMs. In this work, on the basis of defining the false negative issue in discriminative PLMs that has been ignored for a long time, we design enhanced pre-training methods to counteract false negative predictions and encourage pre-training language models on true negatives by correcting the harmful gradient updates subject to false negative predictions. Experimental results on GLUE and SQuAD benchmarks show that our counter-false-negative pre-training methods indeed bring about better performance together with stronger robustness.
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Sequence-to-sequence (seq2seq) learning is a popular fashion for large-scale pretraining language models. However, the prior seq2seq pretraining models generally focus on reconstructive objectives on the decoder side and neglect the effect of encoder-side supervision, which we argue may lead to sub-optimal performance. To verify our hypothesis, we first empirically study the functionalities of the encoder and decoder in seq2seq pretrained language models, and find that the encoder takes an important but under-exploitation role than the decoder regarding the downstream performance and neuron activation. Therefore, we propose an encoding-enhanced seq2seq pretraining strategy, namely E2S2, which improves the seq2seq models via integrating more efficient self-supervised information into the encoders. Specifically, E2S2 adopts two self-supervised objectives on the encoder side from two aspects: 1) locally denoising the corrupted sentence (denoising objective); and 2) globally learning better sentence representations (contrastive objective). With the help of both objectives, the encoder can effectively distinguish the noise tokens and capture high-level (i.e. syntactic and semantic) knowledge, thus strengthening the ability of seq2seq model to accurately achieve the conditional generation. On a large diversity of downstream natural language understanding and generation tasks, E2S2 dominantly improves the performance of its powerful backbone models, e.g. BART and T5. For example, upon BART backbone, we achieve +1.1% averaged gain on the general language understanding evaluation (GLUE) benchmark and +1.75% F_0.5 score improvement on CoNLL2014 dataset. We also provide in-depth analyses to show the improvement stems from better linguistic representation. We hope that our work will foster future self-supervision research on seq2seq language model pretraining.
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Fact verification has attracted a lot of research attention recently, e.g., in journalism, marketing, and policymaking, as misinformation and disinformation online can sway one's opinion and affect one's actions. While fact-checking is a hard task in general, in many cases, false statements can be easily debunked based on analytics over tables with reliable information. Hence, table-based fact verification has recently emerged as an important and growing research area. Yet, progress has been limited due to the lack of datasets that can be used to pre-train language models (LMs) to be aware of common table operations, such as aggregating a column or comparing tuples. To bridge this gap, in this paper we introduce PASTA, a novel state-of-the-art framework for table-based fact verification via pre-training with synthesized sentence-table cloze questions. In particular, we design six types of common sentence-table cloze tasks, including Filter, Aggregation, Superlative, Comparative, Ordinal, and Unique, based on which we synthesize a large corpus consisting of 1.2 million sentence-table pairs from WikiTables. PASTA uses a recent pre-trained LM, DeBERTaV3, and further pretrains it on our corpus. Our experimental results show that PASTA achieves new state-of-the-art performance on two table-based fact verification benchmarks: TabFact and SEM-TAB-FACTS. In particular, on the complex set of TabFact, which contains multiple operations, PASTA largely outperforms the previous state of the art by 4.7 points (85.6% vs. 80.9%), and the gap between PASTA and human performance on the small TabFact test set is narrowed to just 1.5 points (90.6% vs. 92.1%).
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本文介绍了一个新颖的自我监督的细粒度对话评估框架(自我评估)。核心思想是建模转弯质量与整个对话质量之间的相关性。我们首先提出了一种新型的自动数据构建方法,该方法可以自动为任意对话数据分配细粒度的分数。然后,我们使用多层对比度学习模式训练\ textbf {self eval},有助于区分不同的分数水平。多个基准测试的实验结果表明,自我与人类评估高度一致,并且比最先进的模型更好。我们对本文的实验进行了详细的分析。我们的代码和数据将在GitHub上发布。
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预先接受的语言模型(PLM)在神经对话建模中标志着巨大的飞跃。虽然PLMS在大型文本语料库上进行预先培训,但通常在具有特定领域知识和对话风格的稀缺对话数据上进行微调。然而,在大型预先训练模型中充分利用现有知识的同时定制语言模型仍然是一个挑战。在本文中,我们提出了一种预先接受训练的对话建模的新方法,将对话生成问题作为一个快速学习任务。而不是在有限的对话数据上进行微调,我们的方法,DialogPrompt学习针对对话背景优化的连续提示嵌入,从而从大型预训练模型中促进了知识。为了鼓励模型更好地利用提示嵌入,提示编码器被设计为在输入对话框上下文中的条件。流行对话数据集的实验表明,我们的方法显着优于微调基线和通用及时学习方法。此外,人类评估强烈支持对DialialPrompt的优越性在响应生成质量方面。
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这项工作结合了有关预先训练模型编码的对话历史的信息,其含义表示当前系统话语,以实现面向任务对话中的语境语言生成。我们利用预先训练的多上下文转换模型进行从头开始培训的模型中的上下文表示;并利用从预训练的GPT-2调整的模型中的上下文生成的立即使用前面的用户话语。与多种数据集的两个实验表明,通过预先训练的模型编码的上下文信息可提高自动指标和人类评估中的响应生成的性能。我们所呈现的上下文发电机使得更高种类的响应能够更好地适应正在进行的对话。分析上下文大小显示,较长的上下文不会自动导致更好的性能,但是前面的用户话语的直接对上下文生成起着重要作用。此外,我们还提出了一种基于GPT的生成模型的重新排名。实验表明,RE-Ranker选择的响应对自动度量有重大改进。
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用于预培训语言模型的自我监督学习的核心包括预训练任务设计以及适当的数据增强。语言模型中的大多数数据增强都是独立于上下文的。最近在电子中提出了一个开创性的增强,并通过引入辅助生成网络(发电机)来实现最先进的性能,以产生用于培训主要辨别网络(鉴别者)的上下文化数据增强。然而,这种设计引入了发电机的额外计算成本,并且需要调整发电机和鉴别器之间的相对能力。在本文中,我们提出了一种自增强策略(SAS),其中单个网络用于审视以后的时期的培训常规预训练和上下文化数据增强。基本上,该策略消除了单独的发电机,并使用单个网络共同执行具有MLM(屏蔽语言建模)和RTD(替换令牌检测)头的两个预训练任务。它避免了寻找适当大小的发电机的挑战,这对于在电子中证明的性能至关重要,以及其随后的变体模型至关重要。此外,SAS是一项常规策略,可以与最近或将来的许多新技术无缝地结合,例如杜伯塔省的解除关注机制。我们的实验表明,SAS能够在具有相似或更少的计算成本中优于胶水任务中的电磁和其他最先进的模型。
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Knowledge-grounded dialogue systems powered by large language models often generate responses that, while fluent, are not attributable to a relevant source of information. Progress towards models that do not exhibit this issue requires evaluation metrics that can quantify its prevalence. To this end, we introduce the Benchmark for Evaluation of Grounded INteraction (BEGIN), comprised of 12k dialogue turns generated by neural dialogue systems trained on three knowledgegrounded dialogue corpora. We collect human annotations assessing the extent to which the models' responses can be attributed to the given background information. We then use BEGIN to analyze eight evaluation metrics. We find that these metrics rely on spurious correlations, do not reliably distinguish attributable abstractive responses from unattributable ones, and perform substantially worse when the knowledge source is longer. Our findings underscore the need for more sophisticated and robust evaluation metrics for knowledge-grounded dialogue. We make BEGIN publicly available at https://github.com/ google/BEGIN-dataset.
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